Undertale: Tesla and Hanna
by ChalkBoxGamer
Summary: Tesla Arka falls into the Underground after killing his mum. Hanna also falls in after trying to stop Tesla. What happens next? Rated K for minor death mention
1. Naivety and Sacrifices

I do not own Undertale or Hanna. They belong to Toby Fox and GamerFan369 respectively.

Tesla Arka had been climbing Mt Ebbot when he tripped down a hole. It wasn't the worst thing that had happened today, it could even be the best. Legends tell that those who climbed Mt Ebott would never be seen again. He fell onto a patch of flowers that reduced the pain although it still hurt.

Hanna McCallen was having a normal day until she saw a young boy beginning to climb Mt. Ebbot. She had just finished dropping something off at a neighbors house when she noticed him. Frowning and wondering what he was doing, since nobody climbed Mt. Ebbot, she decided to follow him.

She kept about a hundred paces behind him, making sure not to be seen as not to scare the boy into thinking she was some crazy stalker. That wouldn't exactly be a fun conversation to have with the police. She kept this up until she noticed that the boy had stumbled upon a large hole. At this point, she ducked behind a tree and just stared.

Why is there a giant hole here? she wondered.

However, that thought quickly fled her mind when she saw the boy trip and fall in.

"Ack! No!" she cried out, jumping out of her hiding spot and rushing towards the hole, hoping to catch the boy.

Maybe it was because she was going to fast, maybe because the rocks fell beneath her, she wasn't quite sure, but the next thing Hannah knew was that she was tumbling into the hole right after the boy.

Tesla looked up and saw a girl from his neighbourhood (they had said hello multiple times but hadn't really known each other) tumbling after him? Was she following him? That didn't matter; the girl was set to land straight on top of him! He rolled out of the way as she landed on the flowerbed. Tesla got up and examined the place.

He noticed a door just down the corridor he was in. He decided to go through but first...

He glanced back at the girl to make sure she was alright. To see if she would respond he yelled over at her "Hello? Are you okay?"

Moaning in pain, Hannah curled into herself. That hurt! However, she thanked the world that she was still alive. At least, she thought she was.

She considered staying curled up in a ball until she heard a boy's voice calling out to her. Forcing her eyes open, she slowly, and painfully, sat up, taking notice that she was currently sitting in a golden bed of flowers.

Looking up, she saw the boy from earlier and, involuntarily, gave a sigh of relief. She put a hand to her heart and smiled slightly. "Thank goodness you're alive. I would have felt terrible if I just sat back and watched you die."

The boy looked shocked. Maybe this girl was a stalker. Pushing the thought away, he stuck out a hand to the girl. "The name's Tesla. What do you mean 'watched you die?' Are you like those criminals? You look old enough after all. How can I trust you?"

Scratching her head, Hannah laughed nervously at the boy's, Tesla's, words. "Sorry if I made you think I was a stalker. I just saw you going up Mt. Ebbot and since nobody ever goes up there, I was both confused and a little worried. So I followed you up, then saw you fall down the hole. I tried to help you, but then, well, I sort of fell in myself." Chuckling again, this time in embarrassment, she remembered that the boy's hand was still held out in front of her. "Oh, right! I forgot to introduce myself. I'm, Hannah, Hannah McCallen." She took the boy's hand and shook it firmly. "As for how you can trust me, well... I guess you'll just have to...?"

"OK, I guess. How d'you feel? If you're alright with it, I'm gonna go through that door." Tesla pointed to the door. It was only a door; how could it harm them?

"Everything's a little sore, but besides that, I'm fine. Thanks for trusting me though." Getting up, Hannah's eyesight followed where Tesla was pointing and she saw that there was, indeed, a door at the end of a long, black hallway near them. "Yeah, I'm alright with you going through it. I think I'll go with you though. Better to stay in pairs than go alone. Besides, it could be the only way out!" Smiling at Tesla determinedly, Hamnah began to walk towards the door whilst Tesla tugged at her. On the other side was a tiny sunflower. It gave the duo a cheesy grin.

"Oh my gosh!" Hannah cried out. "It so cute!"

"Hanna! Be careful! Maybe this is how people di-" Tesla didn't have time to finish his sentence before the flower spoke. "Howdy! I'm Flowey! You two must be new to the Underground!" Tesla asked what the Underground was and instantly regretted it. The flower replied, venom oozing in his voice, "Shut up. I didn't need a reply. Now listen."

Hannah's smile wavered and she took a step away from the flower, or Flowey, as she learned he was called. "Okay," she drawled. "Not as cute, but still pretty cool. How many people can say they've seen a talking flower?" The last sentence and a half were whispered under her breath.

"Whatever. Look." When the two looked around they couldn't see anything but then Tesla noticed a glowing red heart just in front of his chest. "What is that?" He asked yet another question. This time the flower replied with a smile, "That is your SOUL. The very culmination of your being. It starts weak, but will grow stronger with LV. What does that stand for? Why, LOVE of course!"

Tesla didn't trust the flower.

Hannah looked in front of her and realized she also had a heart floating near her chest. The only difference was that her's was jade, unlike Tesla's red. After staring at it in amazement for a moment, she tuned back in to what Flowey was saying.

She admitted to herself that the whole situation seemed a little...off...but she decided to give Flowey the benefit of the doubt. After all, they've only known him for about two minutes, so for all they knew, he might've been feeling a little awkward talking to them, making him act a little strange. So, keeping a smile on her face, she listened intently to what the flower was saying and tried her best to be as friendly as possible.

"You want some LOVE, don't you?" The flower was being very creepy now. The scariest thing was the 5 bullets that had appeared behind him. "Hanna- Hanna!" Tesla was obviously scared. Flowey winked as a star shot out from Tesla's right. "Down here, LOVE is spread through... 'friendliness pellets.' Get some!"

As the pellets closed in on the duo, Tesla shoved Hanna to the ground to his right and all five pellets stuck into him. He collapsed on the ground. Not dead, but weak.

Too weak.


	2. Ruined Ruins

Thanks for GamerFan369 for writing for Sans and Hannah.

Hannah hit the ground hard and groaned. It wasn't as bad as when she had first fallen, but it still hurt. Looking up, she saw Tesla on the ground and gasped in horror. " _Tesla!_ "

Jumping up, she quickly made her way over to the boy and crouched down beside him. Suddenly, Hannah noticed something that looked oddly like an HP bar appear below Tesla's Soul. The yellow in the bar and the numbers next to it kept decreasing until only a fraction was left. _1 HP_. Her gasp quickly turned into a growl as she turned and menacingly glared at the flower. Her smile had transformed into a scowl, her hands into fists, and anyone could tell that she was. Not. Happy. Not at all.

" _You little-_ " She was so angry that the most she could finish her setence with was a growl.

 **"You IDIOT."** The flower sneered at Hannah. "Your friend was smart not to trust me. Hee hee hee. Have fun helping him- there's nothing you can do. Unless..." Flowey looked to his right and saw a pulsing fireball fly towards him. He ripped his roots out of the ground and got blasted away. Hanna knew he was alive, but was at the moment looking at the figure who had thrown the fire. It was a goat, twice the size of Tesla with long droopy ears and two horns. She had a purple robe with a symbol emblazoned on it. She looked at Tesla, then Hanna, then her hand which still had a little bit of fire on. The first words she said were, "What a miserable creature torturing such a poor innocent youth... Two humans? Well, this is interesting..."

"U-um, who are you?" she asked hesitantly, still a bit rattled from the previous events. It also didn't help that Flowey was still in the back of her mind, distracting her a bit. She did everything in her power to stay focused on their savior and Tesla, however.

Tesla had been laid down on a patch of red flowers in the next room. When he finally regained consciousness he stood up only to fall again. Finally he was steady on his feet and noticed a golden star in front of him. He touched it and his SOUL felt like it had had an electric shock. He was determined. He walked up to the marble staircase behind him and climbed it. He went through the huge purple door and on the other side saw Hanna and a goat. He yelled out to Hanna who looked back at him, then told him to hurry up. He ran up to them as the goat greeted him. "Greetings. I assume you feel better, my child. I am Toriel. This is Han-"

"It's okay. I know her." Tesla butted in.

"Oh, alright my chid. Anyway, we are in the RUINS. Follow me!" Toriel took Tesla with her left hand and Hanna with her right and walked them across the right way to solve the first few puzzles, which Toriel explained as "an ancient fusion between doorkeys and diversions."

Still half paying attention to Toriel, Hannah turned to Tesla and smiled apologetically. "I'm sorry for not listening to your warning," she whispered, sadness evident in her voice. "I just always have the motto of "Trust someone until they've proven they can't be trusted," and even though it _does_ sometimes get me into a bit of trouble, I can't help but follow it." She shrugged and chuckled. "But, I do feel _really_ bad about you getting hurt because of me, so I promise I'll make it up to you!" Her apologetic smile once again turned into a determined one. Tesla looked Hanna in the eyes. "You don't need to save me. I feel... like I need to save **you.** You're somehow special. I can... feel it." Tesla shook his head. "Probably nothin'. Besides, my pain can't _flower_ anymore!" Hannah blinked. "For some strange reason, I have a foreboding that this isn't going to be the last pun I hear on this journey." She laughed nonetheless. "And special? If anyone's special here, it's you kid. You're probably the only reason I'm still alive!" Hannah laughed some more. "If I want to get ahead of you any time soon, I'm gonna need to step up my game, and fast!"

Suddenly, the three of them came to a stop. Flowey was in front of them; he had two vines sticking out of his body. Both wrapped around pillars. He gave a manical laugh and disappeared underground, yanking the pillars down. The three ran to the end of the room, where another purple door lay (Toriel had just set it up for her own sake to get out of the Ruins). They ran through it holding hands and came out in a snowing area, obviously a forest. Looking back, it was obvious the Ruins had been destroyed...

Letting go of Toriel's hand and falling into the snow, Hannah tried to catch her breath. "You know," she said after a minute of heavy breathing. She looked up and glared at the now destroyed Ruins. "I'm really starting to hate that flower." However, something about the flower was nagging her at the back of her mind. Shaking her head and marking it as only mild (or maybe extreme?) annoyance for the monster, she stood up and looked at the other two. "Are you okay?" she asked, concern lacing her voice.

"Ye-yes I am." Tesla replied before the most horrible thing yet happened; he began to cry. In his tears you could make out the words "Idiot... another home... destroyed..."

Hannah started to freak out and, out of the corner of her eye, she noticed Toriel beginning to do the same. Rushing over to Tesla, she crouched down and pulled him into a hug, rubbing his back and trying to comfort him. She didn't have any siblings of her own, so she wasn't a hundred percent sure if it was the right thing to do, but it was the only thing she could think of.

"Hey, Tesla, don't cry. It's okay, it's okay. You're not an idiot. There was nothing any of us could do to prevent what happened. It's not your fault. It's not your fault." She made sure to assure him of the last part, because one thing she did know was that children always tended to blame themselves for anything bad that happened. She had to assure him that it was not his fault. Not even a second later, Hannah noticed Toriel speedwalk over, put her arms around the child, and begin comforting him too. Hannah sighed in relief, knowing that if Toriel was doing the same thing as her, what she was doing must be right.

"No. Hanna, Toriel. You don't understand. YOU DON'T UNDERSTAND!!" With that, Tesla rushed off into the forest, crying as he went. Even though she kept a calm demeanor on the outside, Hannah couldn't help but curse Flowey with every fiber of her being on the inside.


	3. Out Of Your Misery

"Wait! Tesla!" Hannah cried out, darting after the crying boy. She heard Toriel yell something about it being dangerous, but at the moment, she didn't really care. Someone's feelings and happiness were more important to her than a couple scratches and bruises on her body after all!

...About five minutes later, however, she sort of wished she had listened to Toriel's warning, because now she was completely lost and Tesla was nowhere in sight.

 _...Well, this escalated quickly._

Tesla looked back. No sign of anyone. He knew he should go back but he had a feeling of being watched. Then he heard it.

"Human. Don't you know how to great a new pal? Turn around and shake my hand." Tesla could deduce that the...monster, he guessed, was holding out their hand.

Meanwhile, Hannah stood at the base of a tree, her eyes wandering up it's trunk until they reached the top. She was bitting her bottom lip.

"Well," she muttered, "I've never been one for climbing trees, but if it could help me find Tesla faster..." She already figured out that Toriel's warning was true (at least, she guessed). She spotted a few monsters, but was lucky enough to stay out of their way. She had yet to deduce if they were dangerous, but better safe than sorry at the moment. She just hoped Tesla hadn't run into a monster and gotten hurt.

Shaking her head to rid the horrible thoughts, Hannah straightened up, grabbed hold of the tree, and began to climb.

Nervous of who this voice could be, he did as they asked, trembling slightly. It was only when Tesla went to shake their hand that he knew this... skeleton... was a prankster. Ppppppbth! The skeleton had hidden a whoopee cushion in their hand. The skeleton laughed out loud and Tesla did too. "That shook me to the bone!"

"heh." The skeleton chuckled a little more when he realized what the boy said. "looks like I'm not the only one with a funny bone here anymore." Both laughed a little more at the pun.

After the laughs died down, the skeleton began talking again. "well, anyone who can appreciate a good pun, let alone make them, at least deserves an introduction. i'm sans. sans the skeleton." This time, Sans actually did shake Tesla's hand, no prank included. "now, i'm not trying to intrude or anything, but what's a kid like you doing in the underground?" The skeleton mumbled something else under his breath, but Tesla couldn't quite pick up what he said.

"Why are trees so much harder to climb than in the movies?! Why?!"

"So. Sans. Up for a trauma story? Thought you were." Tesla was about to start his story when there was a rustle and a grunt from the bushes. Sans' left pupil glowed blue as he almost yelled "who's there?" He somehow parted the bush to reveal Hannah trying to climb a tree. Tesla ran forward, trying to protect Hannah as a bone flew toward her. Instead, Sans manoeuvred it away into the distance. "oh. another human?" Tesla ran forward, crying again. "I'm so sorry I ran, forvgive me Hannah..." Tesla cried and cried and moved forward. Suddenly, he (awkwardly) hugged the girl in front of him.

One moment, Hannah was (badly) attempting to climb a tree, and the next she was being tackled by a, admittedly rather awkward, hug. She was very confused for a second until she looked down and noticed that it was Tesla who was hugging her. A giant happy, relieved grin lit up her face. "Tesla!" she shouted. Grabbing the boy, she began hugging him like there was no tomorrow. She was so happy to see him alright that she didn't quite hear what he said, but it sounded something like an apology.

After a moment, she pulled back and smiled kindly at Tesla, noticing his tear-stained cheeks. "It's okay. You're already forgiven. Just...please don't scare Toriel and me like that again, okay?" Her eyes widened. "Ack! I just realized. We left Toriel behind! She's probably looking for us and worried sick." Even though she hadn't known the goat for long, Hannah could tell Toriel was the motherly type and would clearly be worried if someone she knew went running off. "We have to go find her!"

Hannah finally looked up and noticed Sans standing off to the side. "Oh!" she exclaimed, their current mission temporarily stopping. "I'm sorry, I didn't notice you were there." Walking up to the skeleton, Tesla behind her, Hannah held out a hand in greeting. "Hi! I'm Hannah! Nice to meet you!"

Sans examined the rather cheery girl before taking her hand. "i'm sans the skeleton."

Obviously almost out of breath, Toriel rushed up to Sans and scrutinised him. Pleased, she announced, "Greetings, I am Toriel, protector of these children. Oh, you are both here! Brilliant!" She pulled Tesla away and gave him a death glare. Tesla sheepishly smiled back at her.

Hannah and Sans couldn't help but laugh at Toriel's and Tesla's reactions.

And wow, Hannah thought. She has pretty convenient timing.

"Oh. Sans. I recognise your voice!" Toriel exclaimed. "yeah, yours does sound familiar. sounds like the voice from..." "THE DOOR?!" Toriel was shocked. She was finally meeting this pun-making person. She grabbed his whoopee cushion hand and shook it firmly. Tesla sniggered and he had to turn his back.

Hannah blinked in confusion at what was happening in front of her. "I'm not one hundred percent sure what is happening, but I think it's important." She turned to Tesla, who was still laughing (along with Toriel and Sans, it seemed). "Except for the whoopee cushion part. I'm pretty sure that has nothing to do with what the two of them just said."

Once his laughing died down, Sans put a hand to the back of his head in an almost sheepish manner. "heh. it's a long story, kid." His eyes began to dart around the area, as if looking for something. "one that we do not have time for." "

Well, who wants to hear my story? Good." Tesla took a deep breath and began. "So to make a shortish story short, whilst helping Dad with an experiment (he was that kind of person, always melting things) I knocked over a pot of molten metal. That spilled and the house went up in flames. Only--" Tesla started choking up, "Only Dad made it through the blaze," he whispered.

"Oh." Hanna whispered sympathetically to Tesla. Walking over, she gave him yet another comforting hug. "I am so, so sorry this happened to you." She didn't know what else she could say, so she only hugged the boy in silence. Toriel decided to just stand back this time while Sans watched on rather awkwardly.

After a minute or so, Hannah pulled back. "Well, do you feel any better after talking about it?"

"Golly, I certainly do!" Flowey had appeared again and used his vines to grab Sans, Toriel and Hannah. "What a sad, sad story. Boo hoo." Flowey's face contorted into a creature beyond horror. "I'll put you out of your misery. I'LL MAKE YOUR FRIENDS WATCH YOUR DEATH." With the sentence, he fired a undodgeable wave of pellets at Tesla. He took them all and fell to the ground. Flowey let go of the vines as everyone rushed towards Tesla. But it was too late. He was dead.

 **Tesla... Tesla, wake up! For the sake of humans and monsters... You have to stay determined!**


End file.
